Initial commit for Chrome metainstaller on Mac.

chrome/installer/mac/app/OmahaCommunication.m

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import <Foundation/Foundation.h>
+#include "OmahaCommunication.h"
+
+@implementation OmahaCommunication : NSObject
+
+@synthesize requestXMLBody;
+@synthesize sessionHelper;
+
+- (id)init {
+  return [self initWithBody:[[NSXMLDocument alloc] init]];
+}
+- (id)initWithBody:(NSXMLDocument*) xmlBody {
+  if ((self = [super init])) {
+    sessionHelper = [[NetworkCommunication alloc] init];
+    requestXMLBody = xmlBody;
+  }
+  return self;
+}
+
+- (NSURLRequest*)createOmahaRequest {
+  NSMutableURLRequest* request = [sessionHelper

[Elly Fong-Jones, 2016/07/06 15:22:01]

Hm, is there a reason for this function to be separate from the initializer? ie,
will anyone ever want to call the initializer and not call this function once
immediately afterward?

+      createRequestWithURLasString:@"https://tools.google.com/service/update2"

[Elly Fong-Jones, 2016/07/06 15:22:02]

this should probably be a constant somewhere, and maybe override-able with a
commandline argument for testing

[Anna Zeng, 2016/07/07 15:24:53]

how do we accomplish this?

+                           andXMLBody:requestXMLBody];
+  request.HTTPMethod = @"POST";
+  return request;
+}
+
+- (void)setResponseHandlingWithBlock:(AfterBlock)blockToRunAfter {
+  DataTaskCompletionHandler cHandler = ^(NSData* _Nullable data,
+                          NSURLResponse* _Nullable response,
+                          NSError* _Nullable error) {
+    if(error) {

[Elly Fong-Jones, 2016/07/06 15:22:02]

I think we need to notify the user of this class that an error happened somehow
other than NSLog. Ideally the user-supplied callback would take an optional
NSError* argument so they can get the error and pass it back up.

+      NSLog(@"%@", error);
+      return;
+    }
+
+    NSHTTPURLResponse* HTTPResponse = (NSHTTPURLResponse*)response;
+    if(HTTPResponse.statusCode != 200) {
+      NSLog(@"HTTP response: %ld", (unsigned long)HTTPResponse.statusCode);
+      return;

[Elly Fong-Jones, 2016/07/06 15:22:01]

same comment - we need a better way to indicate this error.

+    }
+
+    // run block here

[Elly Fong-Jones, 2016/07/06 15:22:01]

this comment doesn't seem like it adds much to understanding this function.

+    blockToRunAfter(data);
+
+  };
+
+  [sessionHelper setDataResponseHandler:cHandler];
+}
+
+- (void)sendRequest {
+  [sessionHelper sendDataRequest];

[Elly Fong-Jones, 2016/07/06 15:22:01]

I could collapse this and setResponseHandlingWithBlock: into the same function.

+}
+
+@end